lusolve

Arguments

b

full real matrix

A

real square sparse invertible matrix

hand

handle to a previously computed sparse lu factors (output of lufact)

x

full real matrix

Description

x=lusolve(hand,b) solves the sparse linear system A*x = b.

[hand,rk]=lufact(A) is the output of lufact.

x=lusolve(A,b) solves the sparse linear system A*x = b

Examples

non_zeros=[1,2,3,4];
rows_cols=[1,1;2,2;3,3;4,4];
sp=sparse(rows_cols,non_zeros);
[h,rk]=lufact(sp);
x=lusolve(h,[1;1;1;1]);
ludel(h)
rk,sp*x

non_zeros=[1,2,3,4];
rows_cols=[1,1;2,2;3,3;4,4];
sp=sparse(rows_cols,non_zeros);
x=lusolve(sp,-ones(4,1));
sp*x

See also

• sparse — sparse matrix definition
• lufact — sparse lu factorization
• slash — (/) right divisions. System's feed back. Comments
• backslash — (\) left matrix division: Exact or least square solution